qxl-test clip: create clip functionalaty

Not tested
Merge branch 'master' into clip_move

master commit appears after clip_move creation
qxl-test clip: done
qxl-test: pre-merge commit
Merge branch 'clip_move'

Conflicts:
	src/test_display_base.c
qxl-test:   All works (no surface images)

clipping, nice drawing